1366 - Incorrect integer value: '' for column 'customer_id' at row 1

insert into whos_online (customer_id, full_name, session_id, ip_address, time_entry, time_last_click, last_page_url) values ('', 'Guest', '836c363e904c7b49456beefc05602d6f', '34.229.24.100', '1563484965', '1563484965', '/index.php/cat/c458_Sexus.html')

[XT SQL Error]